A. To determine the in vivo interindividual variability in the intracellular pharmacokinetics of ZDVTP in peripheral blood mononuclear cells, after a single dose and at steady-state on chronic administration of ZDV, in clinically asymptomatic HIV-infected subjects. B. To determine the change, if any, in steady-state ZDVTP pharmacokinetics over time. C. To simultaneously determine the intracellular concentration-time profile of thymidine triphosphate.